The present application claims priority under 35 U.S.C. xc2xa7119 of German Patent Application No. 101 10 695.5 filed on Mar. 6, 2001, the disclosure of which is expressly incorporated by reference herein in its entirety.
1. Field of the Invention
The invention relates to a self-adjusting deflection controlled roll comprising a rotating roll jacket, a carrier which passes axially through the roll jacket and which is rotationally fixedly held at its ends in racks, and at least one support member arranged at the carrier and exerting a support force on the inner side of the roll jacket in a pressing plane, with at least one axial end of the roll jacket or an axial continuation associated with this being rotatably mounted by at least one bearing on a non-rotating axial bearing sleeve of a bearing housing secured against rotation extending into the region between the roll jacket or the axial continuation and the carrier, said bearing housing being freely movable relative to the carrier substantially in the pressing plane perpendicular to the roll axis. A self-adjusting deflection controlled roll of this kind is known, for example, from EP-A-0 787 912.
2. Discussion of Background Information
Such adjustable deflection rolls are frequently used in practice in the pressing and smoothing sections of paper making machines, wherein they can in particular be designed as so-called self-adjusting rolls in which the roll jacket can be displaced by several centimeters relative to the carrier, in particular by the support members, in order to open and close the pressing jacket.
In the deflection controlled roll known from EP-A-0 787 912, the relevant bearing housing is guided outside the bearing sleeve in the pressing plane perpendicular to the roll axis at a guide ring rotatably held at the carrier and comprising a guide flange and rotatably and tiltably held at the carrier by a pivot bearing with a spherical bearing surface. The roll jacket can be secured against rotation at the carrier by guide members axially arranged between the bearing sleeve and a radial ring surface of the carrier.
It is the aim of the invention to provide an improved deflection controlled roll of the kind initially named. In this connection, among other things, a bearing which is as compact as possible and self-guiding as possible and an introduction of force which is as central as possible in the region of this bearing should be achieved.
This object is satisfied in accordance with the invention in that the roll jacket is radially supported at the carrier transversely to the pressing force plane via the axial bearing sleeve of a respective bearing housing and is axially fixed at the carrier at an axial end via a guide device radially provided between the bearing sleeve of the relevant bearing housing and the carrier and allowing both a tilting movement and a movement of the bearing sleeve substantially in the pressing plane perpendicular to the roll axis. In this connection, the guide device radially provided between the bearing sleeve and the carrier are preferably arranged in an axially central region of the bearing sleeve and/or centered relative to this bearing sleeve in an axial direction.
With this design, in particular an extremely compact, self-guiding bearing results in whose region a central force introduction is possible. Moreover, the bearing housing is always oriented in accordance with the roll jacket independently of the respective roll strain or roll deflection so that in particular no tilting can occur between the roll jacket and the bearing housing even with a more pronounced roll deflection. Jamming effects are practically precluded in the region of the guide device allowing a tilting movement. Both the radial guiding and the axial guiding of the roll jacket are ensured at the same time via the relevant transmission bearing.
The bearing sleeve is expediently also supported radially at the carrier transversely to the pressing plane via the guide means.
In a preferred practical embodiment of the deflection controlled roll in accordance with the invention, the guide device includes at least one guide member rotatably mounted in the bearing sleeve or the carrier about an axis perpendicular to the pressing plane, said guide member sliding as a follower in a guide provided at the carrier or at the bearing sleeve and being displaceably guided by this substantially parallel to the pressing plane perpendicular to the roll axis. In this connection, these guide devices can in particular include at least two follower-like guide members provided at opposing sides of the carrier and respectively cooperating with a guide.
The guide cooperating with a respective guide member can, for example, be formed at a counter-plate secured at the carrier or at the bearing sleeve.
The guide member rotatably mounted in the bearing sleeve or in the carrier can in particular be formed by a spigot with a collar or the like.
The roll jacket is advantageously axially fixed at the carrier at the axial end at the drive side via the guide means associated with a relevant bearing housing.
The roll jacket is advantageously supported radially at the carrier at the other axial end, preferably at the guide side, transversely to the pressing force plane via the axial bearing sleeve of a relevant bearing housing, but axially displaceable relative to said carrier. In this connection, the bearing sleeve of the relevant bearing housing is expediently radially supported at the carrier via at least two bearing members which are arranged at mutually opposing carrier sides and which are each rotatably mounted in the bearing sleeve or in the carrier about an axis perpendicular to the pressing plane. The bearing members rotatably mounted in each case in the bearing sleeve or the carrier about an axis perpendicular to the pressing plane can cooperate with a counter surface which is preferably formed by a counter plate secured to the carrier or to the bearing sleeve.
In a preferred practical embodiment of the deflection controlled roll in accordance with the invention, at least one piston in cylinder arrangement acting generally in the pressing plane perpendicular to the roll axis is provided radially between the bearing sleeve of a respective bearing housing and the carrier. In this respect, at least one piston in cylinder arrangement arranged at the support member side of the carrier and/or at least one piston in cylinder arrangement arranged at the opposite carrier side can be provided.
Such a piston in cylinder arrangement can in particular serve to relieve the roll jacket of the weight force acting outside the working width of the roll jacket and/or to load or relieve the respective jacket end in order to influence the pressing force distribution in the press nip by controlled pressure medium loading and/or to fix the roll jacket in place in a position raised by a counter roll by shutting off the pressure medium backflow from the piston in cylinder arrangement.
The bearing sleeve of a respective bearing housing can in particular be provided in the region of a carrier spigot which is narrowed relative to the axially central region of the carrier. The piston in cylinder arrangement can thus in particular be arranged between the narrowed carrier spigot and the bearing bush, where there is sufficient room available.
The piston of the piston in cylinder arrangement loading the bearing sleeve can comprise a relief chamber fed with pressure fluid at the side of the piston confronting the bearing sleeve, whereby the axial forces or friction forces which occur can be reduced. In this connection, the relief chamber can be fed via at least one capillary. The feeding of the relief chamber can take place via the pressure chamber of the piston in cylinder arrangement through the piston or from the side of the bearing sleeve.
The piston in cylinder arrangement can directly contact the inner side of the bearing sleeve or a shallow side of an intermediate member arranged between the carrier and the bearing sleeve. In the latter case, the advantage results that the piston does not have to be matched to the curved inner side of the guide sleeve.
In a preferred practical embodiment, at least one axial end of the roll jacket or the axial continuation associated with this is rotatably mounted on the bearing sleeve by two bearings axially spaced apart. In this connection, the two axially spaced apart bearings are preferably formed in each case by a roller bearing.
The deflection controlled roll can be designed as a single-zone roll, in which at least the support members can be loaded with the same pressure, or as a multi-zone roll, in which at least some of the support members can be loaded with different pressures.
In a preferred practical embodiment, the drive-side axial end of the roll jacket or the axial continuation associated with this carries a ring gear serving for the roll drive at the radial outside.
It is of advantage if the axial centers of the gear ring, of the bearing arrangement rotatably holding the roll jacket at the bearing housing, of the guide device and/or of the piston in cylinder arrangement essentially lie in a common plane extending perpendicular to the roll axis. It is thus excluded that torques arise in operation which can act disadvantageously on the toothed engagement of the drive toothed arrangement so that the toothed flanks can ideally contact one another within the framework of the bearing clearances in the main bearings.
In particular a favorably priced deflection adjustment roll for compact and lever free press arrangements can be realized on the basis of the solution in accordance with the invention. The roll can be oscillation damping and is suitable for fast-running paper making machines. Only one universally usable deflection adjusting roll type is required for all DuoCentri presses, combination presses and free standing presses with a nip width of less than or equal to 5200 mm (xe2x80x9clean standardxe2x80x9d).
In contrast to the previously usual self-adjusting deflection controlled rolls, the bearing or transmission housing and the roll jacket can be mounted inside the roll jacket hollow spigot in that a collar hub or bearing sleeve connected to the bearing housing accepts the non-rotating inner bearing ring. This non-rotating bearing sleeve at the same time takes on the task of radial roll jacket support transversely to the nip direction.
The axial fixing of the roll jacket to the carrier can take place via the guide part at the drive side which is rotatably inserted into the bearing sleeve and which is guided as a follower in the nip direction, for example in a counter plate secured to the carrier. The radial and axial guiding of the roll jacket is thus given at the same time by the transmission bearing correspondingly designed therefor.
The previously usual expensive self-aligning roller bearing, with follower track, arranged at the jacket end can be omitted. The support members or support sources can thus be placed more closely to the roll rim.
A hydraulic pressure piston can be arranged at the centre of the transmission beneath the non-rotating bearing sleeve provided in particular as a follower ring, with a loading being possible in and/or opposite to the nip direction by one or more hydraulic pressure pistons.
It is, for example, possible to set a variable cambering by the pressure pistons arranged far outside at both sides in that, for example, a single zone hydrostatic support source row is loaded at the same time as the pressure pistons.
When the pressing rolls are arranged at the top, the pressure pistons arranged beneath the bearing simultaneously serve the jacket raising.
The housing can be in one part due to the transmission bearings arranged inside the hollow spigot or the axial continuation, whereas it was previously in three parts. The radial shaft sealing ring normally arranged between the transmission housing and the roll spigot and forming a wear part can thus be replaced very easily without the transmission housing having to be taken apart and resealed. The roll bearing can remain in place.
The gear ratio between the pinion and the outer toothing at the hollow spigot is much more favorable so that, at machine speeds of between 1000 and 1500 m/min for example, the ideal gear ratios can be realized in the same transmission housing without a model change. For instance, in particular a direct drive with a motor, without an additional transmission, is possible. A saving in construction room and costs accordingly results.
Simpler carrier design possibilities result with a box section and, in the case of single zone design, cylinder blocks. The roll becomes lighter and has a low-notch transition at the carrier end. The oil backflow can be realized, for example, in the section hollow chambers.
As hydrostatic counter support sources can be omitted in the jacket region, lower roll jacket deformations (oval shell deformation) result. Even thinner jacket wall thicknesses than with the previously usual self-adjusting multi-zone deflection controlled rolls are perhaps possible.
A lower energy consumption results with the counter forces applied by the outlying pistons (without capillary).
A simpler, freely designable support design is possible, with the guide side and the drive side being similar. The roll has fewer components and now only four anti-friction bearings (two bearing types). The roll is substantially lighter for roll diameters (e.g.xe2x89xa7700 nm) required by the technology than a previously usual floating roll.
The previously known, frequently problematic transmission vibrations in the conventional self-adjusting deflection adjustment rolls as a result of the cantilever support subjected to low load can now be suppressed or damped by the piston force support and by the friction influence at the axial and radial jacket guide. In comparison to the previously usual self-adjusting deflection adjustment rolls, lower manufacturing costs result for the roll, which is in particular due to the reduction in parts and the simpler carrier design. Moreover, a much more favorable and simpler control is possible.
Substantial arrangement advantages result with respect to the previously usual floating roll with an outer pressing system via levers. These include, for example, a simpler and more cost favorable roll stool, a simpler felt and roll replacement, a more compact design despite the larger roll (more free space for the arrangement of scrapers, spray tubes, suction bladders, etc.), planning benefits for conversion work with low construction space and a simple design which is service friendly, operator friendly and safe in operation.
The roll design in accordance with the invention is suitable both for steel jackets and for elastomer jackets. Since no pre-crowning is required at the internally supported roll with the elastomer jacket, the pistons arranged under the roll bearing can be used as carrier pistons for the overhanging loads (transmission and bearing). As already mentioned, the roll can also be designed as a multi-zone roll and be used outside the press part, e.g. in smoothing works.
To keep the axial force of the main bearings as a consequence of the jacket or carrier expansion small, the contact surface from the piston to the bearing sleeve can be provided with at least one hydrostatic relief chamber fed through a capillary. The actual axial force or friction force in this case is only:
Fa=sleeve surfacexc3x97Pxc3x97xcexc,
where P=pressure and xcexc=friction coefficient.
A further advantage also lies in particular in the central force introduction of stroke piston, bearing, pinion, torque support (inside or outside the housing) and radial forces through the roll jacket. A symmetrical bearing load results from all radial forces. Moreover an optimum pinion engagement is ensured, which means that a stalling of the transmission as a result of bearing clearances is practically precluded. The load piston can lie approximately in the center of gravity of the transmission and can therefore be ideally used also and in particular for torque-free jacket rim relief for elastomer rolls.
A further particular advantage can in particular also be seen in the compact self-guiding bearing (main bearing and guide bearing in one ready for installation). The arrangement of the joint centre line for force, bearing and pinion close to the carrier support allows an ideal line force curve, in particular for a one-zone design. The stretch load deviations are the lower, the closer the pistons directed opposite support sources are arranged at the carrier support.
A simpler assembly and dismantling results overall (no bearing adjustmentxe2x80x94unlike separate taper rolling bearings). Fewer bearings and fewer types of bearings are required. No over-determination of the bearings is present. All in all, a more favorable cost solution is achieved. A more favorable carrier design is possible in the spigot transition region.
The present invention is directed to a self-adjusting deflection controlled roll that includes a rotating roll jacket, a carrier arranged to axially pass through the roll jacket and structured to be held rotationally fixedly at its axial ends, and at least one supporting member structured and arranged at the carrier to exert a support force on an inner side of the roll jacket in a pressing plane. A bearing housing includes a non-rotating axial bearing sleeve with at least one bearing, and at least one of an axial end of or an axial continuation of the roll jacket is rotatably mounted by the at least one bearing on the non-rotating axial bearing sleeve. The bearing housing is secured against rotation and extends into a region between the at least one of the axial end or axial continuation of the roll jacket and the carrier. Further, the bearing housing is structured and arranged to be freely movable relative to the carrier substantially in the pressing plane, and the roll jacket is radially supported transversely to the pressing plane by the non-rotating axial bearing sleeve. A guide device, positioned at an axial end of the carrier and radially between the bearing sleeve and the carrier, is structured and arranged to permit both a tilting moving and a movement of the bearing sleeve relative to the carrier substantially in the pressing plane, and the roll jacket being axially fixed at the axial end of the carrier by the guide device.
According to a feature of the invention, the guide device is arranged in at least one of an axially central region of the bearing sleeve and centered relative to the bearing sleeve in an axial direction.
In accordance with another feature of the instant invention, the bearing sleeve is radially supported at the carrier transversely to the pressing plane via the guide device.
Further, the guide device includes at least one guide member rotatably mounted in one of the bearing sleeve and the carrier about an axis perpendicular to the pressing plane. The at least one guide member is structured and arranged to slide as a follower in a guide provided at one of the carrier or the bearing sleeve and to be displaceably guided essentially parallel to the pressing plane. Further still, the at least one guide member includes at least two follower-like guide members provided on mutually opposite sides of the carrier and each cooperating with a respective guide. The guide, arranged to cooperate with the at least one guide member, is formed at a counter plate secured to the one of the carrier or the bearing sleeve.
According to still another feature of the present invention, the guide member includes comprises a flange with a collar.
The roll jacket is axially fixed to the axial end of the carrier at a drive side via the guide device. Further, the roll jacket is supported radially at a guide side opposite the drive side transversely to the pressing plane via the axial bearing sleeve, and is axially displaceable. The bearing sleeve is radially supported at the carrier via at least two bearing members arranged at mutually opposite carrier sides, and the bearing members are rotatably mounted in one of the bearing sleeve or the carrier for rotation about an axis perpendicular to the pressing plane. Still further, the bearing members cooperate with a counter surface which is formed by a counter plate secured to one of the carrier or the bearing sleeve.
In accordance with a further feature of the invention, at least one piston in cylinder arrangement is structured and arranged to act generally in the pressing plane is provided radially between the bearing sleeve and the carrier. The at least one piston in cylinder arrangement is positioned at least one of a support member side of at least one of the carrier and at an opposite carrier side. The piston in cylinder arrangement is positioned to at least one of relieve the roll jacket from weight forces acting outside a working width of the roll jacket, one of load or relieve a respective jacket end in order to influence a pressing force distribution in a press nip by controlled pressure medium loading, or fix the roll jacket in place in a position raised from a counter roll by shutting off a pressure medium backflow from the piston in cylinder arrangement.
Moreover, the bearing sleeve is positioned in a region of a carrier spigot narrowed with respect to an axially central region of the carrier. A piston in cylinder arrangement is arranged between the narrowed carrier spigot and the bearing sleeve.
Further still, a piston of a piston in cylinder arrangement structured and arranged to act on the bearing sleeve comprises a relief chamber fed with pressure fluid at a side confronting the bearing sleeve. The relief chamber is fed via at least one capillary. The feeding of the relief chamber takes place via a pressure chamber of the piston in cylinder arrangement and through the piston. A feeding of the relief chamber takes place from a side of the bearing sleeve.
According to another feature of the instant invention, a piston of a piston in cylinder arrangement is arranged to directly contact an inner side of the bearing sleeve.
In accordance with a still further feature, a piston of a piston in cylinder arrangement is arranged to contact a shallow side of an intermediate member arranged between the carrier and the baring sleeve.
The at least one of the axial end of or the axial continuation of the roll jacket is rotatably mounted at the bearing sleeve by two axially spaced apart bearings. The two axially spaced apart bearings are each formed by a rolling bearing.
Still further, the at least one supporting member can include a plurality of supporting members arranged to form a single-zone roll, such that the plurality of supporting members are loaded with a same pressure. Alternatively, the at least one supporting member can include a plurality of supporting members arranged to form a multi-zone roll, such that at least some of the plurality of supporting members are loaded with different pressures.
The at least one of the axial end of or the axial continuation of the roll jacket is located at a drive side is arranged to outwardly radially carry a gear ring structured and arranged to the roll drive. Axial centers of at least one of the gear ring, the bearing arrangement, the guide device, and a piston in cylinder arrangement lie substantially in a common plane perpendicular to a roll axis.
According to still another feature of the invention, frames are arranged to rotationally fixedly hold the ends of the carrier.
In accordance with yet another feature of the present invention, the pressing plane is perpendicular to a roll axis.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.